To regulate the body temperature of a patient so as to prevent hypothermia to the patient in a medical environment, an inflatable convective blanket that provides a constant stream of warmed air is used. To provide uniform warmth to the patient, after heated air is input to the blanket for inflating the same, the flow pattern of the heated air, as well as the output of the warmed air from the blanket, needs to be regulated or guided in such a way as to eliminate, as much as possible, the difference in temperature of the warmed air output from the area of the blanket close to where the heated air is input to the blanket and the area of the blanket far away from where the heated air is input to the blanket.
One of the ways in which the prior art attempts to regulate the patterns of the flow of air in the blanket as well as to equalize the temperature of the heated air output from the various sections of a convection blanket is disclosed in U.S. Pat. No. 5,324,320, and its progeny U.S. Pat. Nos. 6,287,327 and 6,558,413. Those patents disclose a blanket that has a number of inflation cuffs, or tubes, longitudinally aligned along the length of the blanket. Passageways are provided between adjacent inflation cuffs, and staggered from cuff to cuff, so that each passageway would connect only adjacent cuffs and heated air can traverse between the cuffs. To equalize the temperature of the output air, in addition to having vent ports at the blanket, the apertures, or holes, wherethrough the heated air outputs from the blanket are designed into a pattern whereby the density of the apertures from the central portion of the blanket increase from the center portion of the blanket to the outer edges of the blanket. The configuration of the output air apertures of the above-discussed prior art blanket would work so long as the blanket is made up of a number of adjacent inflation cuffs, or tubes, longitudinally formed along the blanket. However, as convective blankets have now evolved into more than just inflatable self-erecting blankets which do not have the adjacent cuff configuration as the prior art blanket disclosed in the '320 patent, the flow pattern of the air in these non-self-erecting convective blankets need to be regulated so that the temperature gradient of the heated air output from such a blanket not vary substantially among the different sections of the blanket.